3639491805 has 16 divisors (see below), whose sum is σ = 5827673664. Its totient is φ = 1939566720.

The previous prime is 3639491777. The next prime is 3639491809. The reversal of 3639491805 is 5081949363.

It is not a de Polignac number, because 3639491805 - 2⁶ = 3639491741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3639491809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73216 + ... + 112425.

It is an arithmetic number, because the mean of its divisors is an integer number (364229604).

Almost surely, 2^3639491805 is an apocalyptic number.

It is an amenable number.

3639491805 is a deficient number, since it is larger than the sum of its proper divisors (2188181859).

3639491805 is a wasteful number, since it uses less digits than its factorization.

3639491805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186956.

The product of its (nonzero) digits is 699840, while the sum is 48.

The square root of 3639491805 is about 60328.2007439307. The cubic root of 3639491805 is about 1538.2027446477.

The spelling of 3639491805 in words is "three billion, six hundred thirty-nine million, four hundred ninety-one thousand, eight hundred five".